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A 67-years-old woman developed subacute oculomotor nerve palsy and cerebellar gait instability while receiving avelumab as immunotherapy for Merkel cell carcinoma. Brain MRI revealed oculomotor nerve T2/FLAIR hyperintensity and contrast enhancement, CSF cell number and protein concentration were slightly increased. Antibodies against intracellular and surface antigens were excluded through commercial assays, but home-made immunohistochemistry on rat brain sections showed a "neurofilament-like" pattern. Antibodies against neuronal intermediate filament (NIF-IgG) were thus tested and resulted positive in both serum and CSF, confirming the diagnosis of NIF-IgG autoimmunity. Avelumab was discontinued and treatment with steroids and intravenous immunoglobulins led to partial improvement.

Background Myofibrillar myopathies (MFM) are a subgroup of protein aggregate myopathies (PAM) characterized by a common histological picture of myofibrillar dissolution, Z-disk disintegration, and accumulation of degradation products into inclusions. Mutations in genes encoding components of the Z-disk or Z-disk-associated proteins occur in some patients whereas in most of the cases, the causative gene defect is still unknown. We aimed to search for pathogenic mutations in genes not previously associated with MFM phenotype. Methods We performed whole-exome sequencing in four patients from three unrelated families who were diagnosed with PAM without aberrations in causative genes for MFM. Results In the first patient and her affected daughter, we identified a heterozygous p.(Arg89Cys) missense mutation in LMNA gene which has not been linked with PAM pathology before. In the second patient, a heterozygous p.(Asn4807Phe) mutation in RYR1 not previously described in PAM represents a novel, candidate gene with a possible causative role in the disease. Finally, in the third patient and his symptomatic daughter, we found a previously reported heterozygous p.(Cys30071Arg) mutation in TTN gene that was clinically associated with cardiac involvement. Conclusions Our study identifies a new genetic background in PAM pathology and expands the clinical phenotype of known pathogenic mutations.

Brody disease is a rare myopathy characterized by exercise-induced muscle stiffness caused by mutations in the ATP2A1 gene. In the largest cohort of Brody patients to date, Molenaar et al. clarify the phenotype and diagnostic possibilities to help improve understanding and recognition of this distinct myopathy., Brody disease is an autosomal recessive myopathy characterized by exercise-induced muscle stiffness due to mutations in the ATP2A1 gene. Almost 50 years after the initial case presentation, only 18 patients have been reported and many questions regarding the clinical phenotype and results of ancillary investigations remain unanswered, likely leading to incomplete recognition and consequently under-diagnosis. Additionally, little is known about the natural history of the disorder, genotype-phenotype correlations, and the effects of symptomatic treatment. We studied the largest cohort of Brody disease patients to date (n = 40), consisting of 22 new patients (19 novel mutations) and all 18 previously published patients. This observational study shows that the main feature of Brody disease is an exercise-induced muscle stiffness of the limbs, and often of the eyelids. Onset begins in childhood and there was no or only mild progression of symptoms over time. Four patients had episodes resembling malignant hyperthermia. The key finding at physical examination was delayed relaxation after repetitive contractions. Additionally, no atrophy was seen, muscle strength was generally preserved, and some patients had a remarkable athletic build. Symptomatic treatment was mostly ineffective or produced unacceptable side effects. EMG showed silent contractures in approximately half of the patients and no myotonia. Creatine kinase was normal or mildly elevated, and muscle biopsy showed mild myopathic changes with selective type II atrophy. Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) activity was reduced and western blot analysis showed decreased or absent SERCA1 protein. Based on this cohort, we conclude that Brody disease should be considered in cases of exercise-induced muscle stiffness. When physical examination shows delayed relaxation, and there are no myotonic discharges at electromyography, we recommend direct sequencing of the ATP2A1 gene or next generation sequencing with a myopathy panel. Aside from clinical features, SERCA activity measurement and SERCA1 western blot can assist in proving the pathogenicity of novel ATP2A1 mutations. Finally, patients with Brody disease may be at risk for malignant hyperthermia-like episodes, and therefore appropriate perioperative measures are recommended. This study will help improve understanding and recognition of Brody disease as a distinct myopathy in the broader field of calcium-related myopathies.

Background Several viruses have been described as causes of acquired inflammatory myopathies; however, the mechanisms by which they cause muscle disease are still unclear. The aim of this study was to describe the laboratory features of benign acute myositis in a small case series. Methods A detailed pathological and serological analysis was performed in five African migrants who developed an acute viral myositis complicated by rhabdomyolysis. Results Muscle biopsies clearly documented an inflammatory myopathy with histological features similar to polymyositis including CD8+ T cells surrounding and invading nonnecrotic muscle fibers, CD68+ macrophages and major histocompatibility complex class I antigen upregulation. In addition, positivity for myositis-specific antibodies (MSA), in particular anti-aminoacyl tRNA synthetases, was found in the serum of two patients. Conclusions Our study demonstrated that T-cell mediated injury occurs in muscle of patients with acute viral myositis, and that MSA may be present in the serum of these patients.

Introduction/aims Stromal Interaction Molecule 1 (STIM1) is a reticular Ca2+ sensor composed of a luminal and a cytosolic domain. Autosomal dominant mutations in STIM1 cause tubular aggregate myopathy and Stormorken syndrome or its variant York platelet syndrome. We aimed to expand the features related to new variants in STIM1. Methods We performed a cross-sectional study of individuals harboring monoallelic STIM1 variants recruited in five tertiary centers involved in a study of inherited myopathies analyzed with a multigene-targeted panel. Results We identified seven individuals (age range: 26-57 years) harboring variants in STIM1, including five novel changes: three located in the EF-hand domain, one in the sterile α motif (SAM) domain and one in the cytoplasmatic region of the protein. Functional evaluation of the pathogenic variants using a heterologous expression system and measuring store-operated calcium entry demonstrated their causative role and suggested a link of new variants with the clinical phenotype. Muscle contractures, found in three individuals, showed variability in body distribution and in the number of joints involved. Three patients showed cardiac and respiratory involvement. Short stature, hyposplenism, sensorineural hearing loss, hypothyroidism and Gilbert syndrome were variably observed among the patients. Laboratory tests revealed hyperCKemia in six patients, thrombocytopenia in two and hypocalcemia in a single patient. Muscle biopsy showed the presence of tubular aggregates in three patients, type I fiber atrophy in one patient, and non-specific myopathic changes in two. Discussion Our clinical, histological and molecular data expand the genetic and clinical spectrum of STIM1-related diseases. This article is protected by copyright. All rights reserved.

Muscular dystrophies in dogs and cats represent a heterogeneous group of inherited, sometimes congenital, but infrequently diagnosed, progressive neuromuscular disorders. A correct identification and characterization of canine and feline muscular dystrophies could increase diagnostic and treatment strategies for veterinary neurologists and could identify useful animal models for the study of human dystrophies. However, in dogs and cats, diagnosis of muscular dystrophies is challenging due to a nonspecific clinical phenotype and pathological lesions, thus is most likely underestimated. We performed immunofluorescence and Western blot techniques using a wide panel of antibodies against proteins involved in human dystrophies (dystrophin mid-rod and carboxyterminal domain, α, β, γ, and δ-sarcoglycan, α-dystroglycan, caveolin-3, emerin, merosin, dysferlin, calpain-3, spectrin epitopes), on 9 canine and 3 feline muscle biopsies characterized by myopathic changes. Dystrophin deficiency was detected in 3 dogs and 2 novel canine muscular dystrophies have been identified, characterized by deficiency of caveolin-3 and calpain-3, respectively. In 2 cats, deficiency of β-SG and carboxyterminal domain of dystrophin in all muscle fibers has been detected. Performing immunofluorescence and Western blot analyses with a wider panel of antibodies allowed a correct identification of muscular dystrophies in dogs and cats and provides a direction for subsequent targeted genetic testing.

Background Camptocormia is a disabling complication of Parkinson's disease (PD), but its pathophysiology is poorly elucidated. Depending on the fulcrum of forward trunk flexion, two subtypes have been defined, upper (UCC) and lower camptocormia, the former being much more frequent. The aim of the study was to explore possible pathophysiological mechanisms of PD-related UCC. Methods Ten PD patients with UCC (UCC-PD) and ten PD patients without camptocormia (NoUCC-PD) underwent simultaneous electromyography (EMG) of thoracic paraspinal (TPS), obliquus externus abdominis (OEA), rectus abdominis (RA), and iliopsoas (IP) muscles during relaxed standing (both groups) and trunk realignment (UCC-PD group). Quantitative EMG and magnetic resonance imaging (MRI) of TPS muscles were also performed. Results UCC-PD patients showed hyperactivity of TPS and OEA muscles in quiet stance. During voluntary trunk extension, hyperactivity of OEA muscles persisted, thus revealing a co-contraction of flexor and extensor trunk muscles. Motor unit potentials (MUP) of TPS muscles showed shorter duration (p = 0.005) and lower amplitude (p = 0.004) in UCC-PD than in NoUCC-PD patients. MRI did not detect significant between-group differences in the cross-sectional area and fat fraction of TPS muscles, although the latter was higher in the UCC-PD than in the NoUCC-PD group at all thoracic levels. Conclusion Our findings suggest that hyperactivity of OEA might sustain UCC in PD. Concurrent mild myopathic changes in TPS muscles in PD with UCC may be secondary to muscle disuse but nevertheless may contribute to abnormal trunk posture.

No abstract available

Background: Chronic graft versus host disease (cGVHD) occurs in 20-30% of paediatric patients receiving haemopoietic stem cell transplantation (HSCT). Neuromuscular disorders such as polymyositis are considered a rare and distinctive but non-diagnostic manifestation of cGVHD and, in absence of other characteristic signs and symptoms, biopsy is highly recommended to exclude other causes. Case report: We report a case of a 17-months-old child affected by hemophagocytic lymphohistiocytosis who underwent a matched unrelated donor haematopoietic stem cell transplantation (HSCT). She developed a severe cGVHD-related polymyositis that was successfully treated with high-dose steroid therapy, rituximab and sirolimus. Conclusions: This is the first case of cGVHD-related-polymyositis described in a pediatric patient which was successfully treated with rituximab.

Multiple acyl-CoA dehydrogenase deficiency, or glutaric aciduria type II, is an autosomal recessive disorder of fatty acid oxidation due to defects in electron transfer flavoprotein (ETF) encoded by ETFA and ETFB, or in electron transfer flavoprotein dehydrogenase (ETFDH) encoded by the ETFDH gene. The disease may present as a severe neonatal onset form and a mild late-onset form which is heterogeneous for the age at onset and clinical presentation. We describe two patients in their seventies, referred for a nonspecific myopathy, which resulted to manifest carriers of ETFDH gene mutation. Treatment with riboflavin and L-carnitine improved the clinical picture and the biochemical profile. This condition should be included in the differential diagnosis of myopathies even at an old age.

Simple Summary Multiple myeloma (MM) is a still uncurable tumor of mainly elderly patients originating from the terminally differentiated B cells. Introduction to the treatment of MM patients of a new class of drugs called proteasome inhibitors (bortezomib followed by carfilzomib and ixazomib) significantly improved disease control. Proteasome inhibitors interfere with the major mechanism of protein degradation in a cell leading to the severe imbalance in the protein turnover that is deadly to MM cells. Currently, these drugs are the mainstream of MM therapy but are also associated with an increased rate of the injuries to multiple organs and tissues. In this review, we summarize the current knowledge on the molecular mechanisms of the first-in-class proteasome inhibitor bortezomib-induced disturbances in the function of peripheral nerves and cardiac and skeletal muscle. Abstract The overall approach to the treatment of multiple myeloma (MM) has undergone several changes during the past decade. and proteasome inhibitors (PIs) including bortezomib, carfilzomib, and ixazomib have considerably improved the outcomes in affected patients. The first-in-class selective PI bortezomib has been initially approved for the refractory forms of the disease but has now become, in combination with other drugs, the backbone of the frontline therapy for newly diagnosed MM patients, as well as in the maintenance therapy and relapsed/refractory setting. Despite being among the most widely used and highly effective agents for MM, bortezomib can induce adverse events that potentially lead to early discontinuation of the therapy with negative effects on the quality of life and outcome of the patients. Although peripheral neuropathy and myelosuppression have been recognized as the most relevant bortezomib-related adverse effects, cardiac and skeletal muscle toxicities are relatively common in MM treated patients, but they have received much less attention. Here we review the neuromuscular and cardiovascular side effects of bortezomib. focusing on the molecular mechanisms underlying its toxicity. We also discuss our preliminary data on the effects of bortezomib on skeletal muscle tissue in mice receiving the drug.

Mitochondrial diseases (MDs) are a group of heterogeneous disorders due to impaired oxidative phosphorylation causing defective ATP production. The histopathological hallmark is the presence ofragged-red fibers (RRFs), muscle fibers with excessive mitochondrial proliferation. Nitric oxide synthases (NOSs) are enzymes responsible of the synthesis of nitric oxide (NO), a ubiquitous signaling molecule involved in many physio-pathological processes. Three NOS isoenzymes have been identified so far including neuronal NOS (NOS1), inducible NOS (NOS2) and endothelial NOS (NOS3). Despite the expression and the subcellular localization of NOS1 and NOS3 have been previously investigated, a possible involvement of NOS2 in MDs has never been assessed. We evaluated the expression of NOS2 in muscle biopsies from 17 patients with mitochondrial respiratory chain dysfunction. Our data demonstrate that NOS2 is overexpressed in RRFs and the correspondence between NOS2 immunoreactivity and SDH staining suggests that the protein localizes to the mitochondria. Together with previous studies from the literature, these findings indicate a possible role NOSs in the pathogenic events leading to MDs

Emery Dreifuss muscular dystrophy (EDMD) is an inherited myopathy characterized by early contractures, slow progressive muscle weakness and cardiac involvement. To date at least seven genes have been associated to EDMD with different inheritance patterns, being emerin gene responsible for the X-linked form of the disease. We report a 40-year-old man who was referred for severe gait difficulty. At age 6 years the patient presented with a waddling gate, lumbar lordosis and heel contractures. Both electrophysiology and muscle biopsy were consistent with a neurogenic disorder and he received a diagnosis of spinal muscular atrophy type 3. At the age of 30 the patient developed heart involvement with junctional escape rhythm and, eight years later, had a spontaneous chordae tendinae rupture. A new clinical examination showed severe muscular weakness and atrophy in scapulohumeroperoneal pattern with significant involvement of the lower facial and intrinsic hand muscles and on a second muscle biopsy emerin was absent by immunohistochemistry and by immunoblot analysis. Sequence analysis of EMD gene revealed the presence of a novel mutation represented by an out-of-frame deletion spanning from the beginning of exon 1 to the half of intron 2 (p.Asp6Glyfs*27). Our study expands the clinical and molecular spectrum of X-linked EDMD.

The use of nanoparticles as drug carriers in the field of skeletal muscle diseases has been poorly addressed and the interaction of nanoparticles with skeletal muscle cells has been investigated almost exclusively on C2C12 murine myoblasts. In this study we investigated the effects poly(lactide-co-glycolide) nanoparticles, mesoporous silica nanoparticles and liposomes, on the viability of primary human myoblasts and analyzed their cellular uptake and intracellular distribution in both primary human myoblasts and myotubes. Our data demonstrate that poly(lactide-co-glycolide) nanoparticles do not negatively affect myoblasts viability, contrarily to mesoporous silica nanoparticles and liposomes that induce a decrease in cell viability at the highest doses and longest incubation time. Poly(lactide-co-glycolide) nanoparticles and mesoporous silica nanoparticles are internalized by endocytosis, poly(lactide-co-glycolide) nanoparticles undergo endosomal escape whereas mesoporous silica nanoparticles always occur within vacuoles. Liposomes were rarely observed within the cells. The uptake of all tested nanoparticles was less prominent in primary human myotubes as compared to myoblasts. Our findings represent the first step toward the characterization of the interaction between nanoparticles and primary human muscle cells and suggest that poly(lactide-co-glycolide) nanoparticles might find an application for drug delivery to skeletal muscle.

Mitochondrial disorders are heterogeneous multisystemic disorders due to impaired oxidative phosphorylation causing defective mitochondrial energy production. Common histological hallmarks of mitochondrial disorders are RRFs (ragged red fibres), muscle fibres with abnormal focal accumulations of mitochondria. In contrast with the growing understanding of the genetic basis of mitochondrial disorders, the fate of phenotypically affected muscle fibres remains largely unknown. We investigated PCD (programmed cell death) in muscle of 17 patients with mitochondrial respiratory chain dysfunction. We documented that in affected muscle fibres, nuclear chromatin is condensed in lumpy irregular masses and cytochrome c is released into the cytosol to activate, along with Apaf-1 (apoptotic protease-activating factor 1), caspase 9 that, in turn, activates effector caspase 3, caspase 6, and caspase 7, suggesting the execution of the intrinsic apoptotic pathway. Whereas active caspase 3 underwent nuclear translocation, AIF (apoptosis-inducing factor) mainly stayed within mitochondria, into which an up-regulated Bax is relocated. The significant increase in caspase 2, caspase 3 and caspase 6 activity strongly suggest that the cell death programme is caspase-dependent and the activation of caspase 2 together with PUMA (p53 up-regulated modulator of apoptosis) up-regulation point to a role for oxidative stress in triggering the intrinsic pathway. Concurrently, in muscle of patients, the number of satellite cells was significantly increased and myonuclei were detected at different stages of myogenic differentiation, indicating that a reparative programme is ongoing in muscle of patients with mitochondrial disorders. Together, these data suggest that, in patients with mitochondrial disorders, affected muscle fibres are trapped in a mitochondria-regulated caspase-dependent PCD while repairing events take place.

M-line is the narrow transverse band located in the center of the sarcomeric A-band that is mainly responsible for the stabilization of myosin thick filaments. A 27-year-old male patient with a positive medical history for ankylosing spondylitis presented with one month of proximal upper limb muscle weakness associated with pain on both acromioclavicular joints. A biopsy of deltoid muscle documented the disappearance of M-line, the misalignment of myofilaments, and the loss of the distinction between the A and I bands. Complete resolution of muscle weakness occurred after one year of treatment with antiTNFα agent Etanercept. Because of the acute onset of symptoms and the recovery after immunosuppressive treatment we hypothesized that an immune-mediated mechanism was responsible for the muscle disorder. The serum IgG-mediated autoreactivity to skeletal muscle antigens resolved by bidimensional electrophoresis was assessed in the described patient and compared with that of control subjects. The comparative analysis of the immunoreactive spots revealed that ATP synthase subunit α is specifically recognized by patient's serum, suggesting that the protein might represent a putative antigenic target in the disease. This study reports an acute reversible myopathy pathologically characterized by M-line involvement and associated with serological antibodies to the subunit α of ATP synthase.

Brody disease (BD, OMIM #601003) is an inherited skeletal muscle disease clinically characterized by exercise-induced impairment of muscle relaxation and stiffness due to the delay in the Ca2+ re-uptake in the sarcoplasmic reticulum (SR)[1, 2]. The delayed muscle relaxation mainly affects legs, harms, hands and eyelids and usually improves after a few minutes rest [1-3]. Patients frequently report myalgia, painless or mildly painful cramps whereas recurrent rhabdomyolysis have been described in a few cases [2, 3]. A reduction in sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) activity characterizes the skeletal muscle of these patients [2-5]. This article is protected by copyright. All rights reserved.

Aims Myofibrillar myopathies (MFMs) are a group of inherited or sporadic neuromuscular disorders characterized morphologically by foci of myofibril dissolution, disintegration of the Z-disk and insoluble protein aggregates within the muscle fibres. The sequential events leading to muscle fibre damage remains largely unknown. Methods and results We investigated the expression and the cellular localization of RNA polymerase II (RNAPII)-associated proteins (RPAPs) in muscle biopsies from patients with genetically proven and sporadic MFMs. Our data demonstrated that RPAP2, and to a lesser extent GPN1/RPAP4, are accumulated focally in the cytoplasm of MFM muscle fibres in which they co-localize with POLR2A/RPB1, the largest subunit of RNAPII, and correspond to αB-cystallin deposits in distribution and staining intensity. No abnormal staining for RPAP2 has been observed in muscle of patients with central cores, minicores and neurogenic target fibres. Conclusions Together, these findings could provide new insights into the molecular pathogenesis of MFMs and suggest that RPAP2 immunostaining can be a useful diagnostic tool to depict protein aggregates in MFMs.

Here, we report the identification of three novel missense mutations in the calsequestrin-1 (CASQ1) gene in four patients with tubular aggregate myopathy. These CASQ1 mutations affect conserved amino acids in position 44 (p.(Asp44Asn)), 103 (p.(Gly103Asp)), and 385 (p.(Ile385Thr)). Functional studies, based on turbidity and dynamic light scattering measurements at increasing Ca2+ concentrations, showed a reduced Ca2+ -dependent aggregation for the CASQ1 protein containing p.Asp44Asn and p.Gly103Asp mutations and a slight increase in Ca2+ -dependent aggregation for the p.Ile385Thr. Accordingly, limited trypsin proteolysis assay showed that p.Asp44Asn and p.Gly103Asp were more susceptible to trypsin cleavage in the presence of Ca2+ in comparison with WT and p.Ile385Thr. Analysis of single muscle fibers of a patient carrying the p.Gly103Asp mutation showed a significant reduction in response to caffeine stimulation, compared with normal control fibers. Expression of CASQ1 mutations in eukaryotic cells revealed a reduced ability of all these CASQ1 mutants to store Ca2+ and a reduced inhibitory effect of p.Ile385Thr and p.Asp44Asn on store operated Ca2+ entry. These results widen the spectrum of skeletal muscle diseases associated with CASQ1 and indicate that these mutations affect properties critical for correct Ca2+ handling in skeletal muscle fibers.

Multiple myeloma (MM) accounts for ∼13% of all hematologic malignancies. Bortezomib treatment is effective in MM, but can be complicated with neurological side effects. We describe a patient with symptomatic MM who had a reversible metabolic myopathy associated with bortezomib administration and pathologically characterized by excessive storage of lipid droplets together with mitochondrial abnormalities. In a single-center prospective study, 14 out of 24 patients with symptomatic MM were treated with bortezomib and, among these, 7 developed muscular signs and/or symptoms. The myopathy was characterized by a proximal muscle weakness involving lower limbs and was an early complication. Complete resolution of muscle weakness occurred after treatment discontinuation. Conversely, none of the patients who received a treatment without bortezomib developed muscular symptoms. Experimental studies demonstrate that in primary human myoblasts bortezomib at low concentrations leads to excessive storage of lipid droplets together with structural mitochondrial abnormalities, recapitulating the pathologic findings observed in patient's muscle. Our data suggest that patients treated with bortezomib should be monitored for muscular signs and/or symptoms and muscle weakness should alert the clinician to the possibility of myopathy. Bortezomib-induced metabolic myopathy is a potentially reversible entity with important implications for management and treatment of patients with MM.

A 59-year-old male patient complained, from age 36, of insidious appearance in several weeks of a circumscribed painful mass, single or multiple, under the skin with hard consistency on palpation. At first, these masses were localised on sural aspect of the legs, thereafter on arms, thighs and, occasionally, on trunk and face. They had a diameter ranging from 3 cm to 5 cm and the overlying skin tissue was normal. Pain might increase with movement causing functional limitation of the corresponding limb. In the first years, they spontaneously remitted within 2–3 months, successively in 6–7 months. Onset of these lesions was never preceded or accompanied by systemic symptoms such as fever, weakness and fatigue. A muscle biopsy was taken …

Mitochondrial diseases (MDs) are heterogeneous disorders due to impaired respiratory chain function causing defective ATP production. Although the disruption of oxidative phosphorylation is central to the MD pathophysiology, other factors may contribute to these disorders. We investigated the expression and the cellular localization of TNF-α and its receptors, TNFR1 and TNFR2, in muscle biopsies from 15 patients with mitochondrial respiratory chain dysfunction. Our data unambiguously demonstrate that TNF-α is expressed in muscle fibers with abnormal focal accumulations of mitochondria, so-called ragged red fibers, and is delivered to mitochondria where both receptors are localized. Moreover TNF receptors are differentially regulated in patients' muscle in which the expression levels of TNFR1 mRNA are decreased and those of TNFR2 mRNA are increased compared with controls. These findings suggest for the first time that TNF-α could exert a direct effect on mitochondria via its receptors.

Brody disease is a rare inherited myopathy due to reduced sarcoplasmic reticulum Ca(2+) ATPase (SERCA)1 activity caused by mutations in ATP2A1, which causes delayed muscle relaxation and silent cramps. So far the disease has mostly been diagnosed by measurement of SERCA1 activity. Since mutation analysis became more widely available, it has appeared that not all patients with reduced SERCA1 activity indeed have ATP2A1 mutations, and a distinction between Brody disease (with ATP2A1 mutations) and Brody syndrome (without ATP2A1 mutations) was proposed. We aim to compare the clinical features of patients with Brody disease and those with Brody syndrome and detect clinical features which help to distinguish between the two. In addition, we describe the Brody syndrome phenotype in more detail. We therefore performed a literature review on clinical features of both Brody disease and Brody syndrome and a cross-sectional clinical study consisting of questionnaires, physical examination, and a review of medical files in 17 Brody syndrome patients in our centre. The results showed that Brody disease presents with an onset in the 1st decade, a generalized pattern of muscle stiffness, delayed muscle relaxation after repetitive contraction on physical examination, and autosomal recessive inheritance. Patients with Brody syndrome more often report myalgia and experience a considerable impact on daily life. Future research should focus on the possible mechanisms of reduction of SERCA activity in Brody syndrome and other genetic causes, and on evaluation of treatment options.

BACKGROUND Epoxyeicosatrienoic acids (EETs) derived from cytochrome P450 (CYP)-dependent metabolism of arachidonic acid are increased in the plasma of women with preeclampsia as compared with normal pregnancy and are significantly higher in fetal than in maternal plasma and erythrocytes. We hypothesized that differences in EET synthesis or metabolism in the feto-placental unit contributed to the observed differences in circulating EETs. METHOD To evaluate EETs, formation as well as the expression of relevant CYP isoforms and the metabolizing enzyme, soluble epoxide hydrolase (sEH), biopsies of placenta were collected from 19 normal pregnancy and 10 preeclampsia at the time of cesarean section delivery. EETs were extracted from tissue homogenates and analyzed by liquid chromatography coupled with tandem mass spectrometry. RESULTS Both cis-EETs and trans-EETs were detected in the placenta. Concentration of total EETs was higher in the placenta from preeclampsia compared with normal pregnancy (2.37 ± 1.42 ng/mg vs. 1.20 ± 0.72 ng/mg, mean ± SD, P

Contains fulltext : 167645.pdf (Publisher’s version ) (Closed access) Sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase (SERCA) pumps play the major role in lowering cytoplasmic calcium concentration in skeletal muscle by catalyzing the ATP-dependent transport of Ca(2+) from the cytosol to the lumen of the sarcoplasmic reticulum (SR). Although SERCA abnormalities have been hypothesized to contribute to the dysregulation of intracellular Ca(2+) homeostasis and signaling in muscle of patients with myotonic dystrophy (DM) and hypothyroid myopathy, the characterization of SERCA pumps remains elusive and their impairment is still unclear. We assessed the activity of SR Ca(2+)-ATPase, expression levels and fiber distribution of SERCA1 and SERCA2, and oligomerization of SERCA1 protein in muscle of patients with DM type 1 and 2, and with hypothyroid myopathy. Our data provide evidence that SR Ca(2+) ATPase activity, protein levels and muscle fiber distribution of total SERCA1 and SERCA2, and SERCA1 oligomerization pattern are similar in patients with both DM1 and DM2, hypothyroid myopathy and in control subjects. We prove that SERCA1b, the neonatal isoform of SERCA1, is expressed at protein level in muscle of patients with DM2 and, in lower amount, of patients with DM1. Our present study demonstrates that SERCA function is not altered in muscle of patients with DM and with hypothyroid myopathy.

A 10-year-old neutered female domestic longhaired cat was referred for evaluation of forelimb weakness and lameness. There was hypertrophy and firmness of the musculature with no neurological deficits. Moderate increase of creatine kinase activity was present. Muscle biopsy showed rounded atrophic and hypertrophic fibres, an increased number of centrally located myofibre nuclei, scattered rimmed vacuoles and mild perimysial and endomysial fibrosis. Myofibre necrosis with phagocytosis was present in the gluteal muscle. Immunohistochemistry revealed absence of sarcolemmal caveolin-3 in almost all muscle fibres and sarcoplasmic accumulation of the protein in approximately 30% of myofibres. Normal expression of caveolin-3 was detected by immunoblotting, so protein mislocalization in the sarcoplasm due to aberrant trafficking towards the sarcolemma was suspected. This case represents the first example of muscular dystrophy due to a caveolinopathy in animals.

MDs (mitochondrial diseases) are a clinically heterogeneous group of disorders characterized by impairment of the respiratory chain function with altered oxidative phosphorylation. We tested the hypothesis that the function of vascular endothelium is affected by increased oxidative stress in MDs. A total of 12 patients with MDs and pair-matched controls were studied. Endothelial function was assessed by measuring FMD (flow-mediated vasodilation) of brachial and common femoral arteries. The test was repeated after vitamin C (500 mg, twice a day) and E (400 mg, once a day) supplementation for 30 days and 90 days after vitamin withdrawal. FMD was reduced in patients compared with controls [AUC/τ (time-averaged area under the curve) for the brachial artery, 1.05±0.24 compared with 4.19±0.59% respectively, P

Contains fulltext : 88384.pdf (Publisher’s version ) (Closed access) Brody disease is an inherited disorder of skeletal muscle function characterized by increasing impairment of relaxation during exercise. The autosomal recessive form can be caused by mutations in the ATP2A1 gene, which encodes for the sarcoplasmic/endoplasmic reticulum Ca-ATPase 1 (SERCA1) protein. We studied 2 siblings affected by Brody disease. The patients complained of exercise-induced delay of muscle relaxation and stiffness since childhood and had gene analysis of ATP2A1. Morphologic and biochemical studies were performed on a muscle biopsy from 1 patient. The biopsy showed fiber size variation and increased numbers of fibers with internal nuclei. Ultrastructural examination revealed dilatation of lateral cisternae and proliferation of tubular elements of the sarcoplasmic reticulum. By immunohistochemistry, SERCA1 was expressed in a normal pattern, but sarcoplasmic reticulum Ca-ATPase activity was significantly reduced. Immunoblotting after high-resolution 2-dimensional gel electrophoresis showed a significant difference in the amount of SERCA1 protein between the patient and controls. Both patients were found to have 2 previously unreported in-frame deletions in ATP2A1. Because SERCA1 protein has specific biochemical characteristics in our patient, these results underline the importance of a pathologic and biochemical analyses for the diagnosis. In addition, we describe 2 novel mutations in the ATP2A1 gene. 01 maart 2010

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We tested the hypothesis that maternal peripheral blood leukocytes contribute to elevated levels of soluble TNF receptors (sTNFR) in preeclampsia (PE) with concomitant intrauterine growth restriction (IUGR). TNFR1 and TNFR2 were evaluated in a cross-sectional study comparing preeclamptic (n = 15) with or without IUGR versus normotensive pregnant women (PREG, n = 30), and non-pregnant controls (Con; n = 20). Plasma levels of sTNFR1 were higher in PE (1675.0 ± 227.1 pg/mL) compared with PREG (1035.0 ± 101.1 pg/mL) and Con (589.3 ± 82.67 pg/mL), with the highest values observed in PE with IUGR (2624.0 ± 421.4 pg/mL; n = 6). Plasma sTNFR2 was higher during pregnancy (PE: 1836.0 ± 198.7 pg/mL; PREG: 1697.0 ± 95.0 pg/mL) compared with Con (598.3 ± 82.7 pg/mL). Urinary levels of sTNFR1 and sTNFR2 were higher in PE and PREG compared with the Con group. Abundance of TNFR1 mRNA in peripheral blood leukocytes was strongly correlated with plasma levels of sTNFR1 in PE. However, TNFR2 mRNA accumulation in leukocytes did not correlate with sTNFR2 plasma levels. The level of sTNFR1 in plasma was correlated with body weight of the newborn (r = -0.56). The data suggest that maternal leukocytes contribute to sTNFR1 levels in plasma in association with decreasing newborn weight and PE with concomitant IUGR.

We describe four patients, from four different families, affected by a mild myopathy or asymptomatic elevated serum creatine kinase levels, in whom toluidine blue-stained semithin sections of muscle specimens revealed inclusions of different size and shape. The inclusions did not stain by routine histochemical studies. The sarcoplasmic or endoplasmic reticulum calcium 1 (SERCA1) ATPase and/or calsequestrin reactivity of inclusions, by immunohistochemistry, and the SERCA1- and calsequestrin-increased expression, by immunoblot, suggested that inclusions were constituted by an excess of proteins normally present in the terminal cisternae of sarcoplasmic reticulum. Our cases, both sporadic and familial, represent a new type of surplus protein myopathy.

Proteins in the endoplasmic reticulum (ER) require an efficient system of molecular chaperones whose role is to assure their proper folding and to prevent accumulation of unfolded proteins. The response of cells to accumulation of unfolded proteins in the ER is termed "unfolded protein response" (UPR). UPR is a functional mechanism by which cells attempt to protect themselves against ER stress, resulting from the accumulation of the unfolded/misfolded proteins. Because intracellular inclusions, containing either amyloid-beta (Abeta) or phosphorylated tau, are the characteristic feature of sporadic inclusion body myositis (s-IBM) muscle biopsies, we studied expression and immunolocalization of five ER chaperones, calnexin, calreticulin, GRP94, BiP/GRP78, and ERp72, in s-IBM and control muscle biopsies. Physical interaction of the ER chaperones with amyloid-beta precursor protein (AbetaPP) was studied by a combined immunoprecipitation/immunoblotting technique in s-IBM and control muscle biopsies, and in AbetaPP-overexpressing cultured human muscle fibers. In all s-IBM muscle biopsies, all five of the ER chaperones were immunodetected in the form of inclusions that co-localized with amyloid-beta. By immunoblotting, expression of ER chaperones was greatly increased as compared to the controls. By immunoprecipitation/immunoblotting experiments, ER chaperones co-immunoprecipitated with AbetaPP. Our studies provide evidence of the UPR in s-IBM muscle and demonstrate for the first time that the ER chaperones calnexin, calreticulin, GRP94, BiP/GRP78, and ERp72 physically associate with AbetaPP in s-IBM muscle, suggesting their playing a role in AbetaPP folding and processing.

Cultured muscle fibers (CMF) from a patient with inclusion-body myositis (IBM) and cardiac amyloidosis associated with the transthyretin (TTR) Val122Ile mutation contained aspects of the IBM phenotype: vacuolation, congophilic inclusions, and clusters of immunocolocalizing amyloid beta-peptide (Abeta) and TTR accumulations. These abnormalities are never present in normal human CMF. These perturbations were greatly increased after Abeta precursor protein gene transfer. The TTR mutation may be a genetic predisposition factor for the patient's IBM.

Cystatin C (CC), an endogenous cysteine protease inhibitor, is accumulated within amyloid-β (Aβ) amyloid deposits in Alzheimer's disease (AD) brain and was proposed to play a role in the AD pathogenesis. Because the chemo-morphologic muscle phenotype of sporadic inclusion-body myositis (s-IBM) has several similarities with the phenotype of AD brain, including abnormal accumulation of Aβ deposits, we studied expression and localization of CC in muscle biopsies of 10 s-IBM, and 16 disease- and five normal-control muscle biopsies. Physical interaction of CC with amyloid-β precursor protein (AβPP) was studied by a combined immunoprecipitation/immunoblotting technique in the s-IBM muscle biopsies and in AβPP-overexpressing cultured human muscle fibers. In all s-IBM muscle biopsies, CC-immunoreactivity either colocalized with, or was adjacent to, the Aβ-immunoreactive inclusions in 80–90% of the vacuolated muscle fibers, mostly in non-vacuolated regions of their cytoplasm. Ultrastructurally, CC immunoreactivity-colocalized with Aβ on 6–10 nm amyloid-like fibrils and floccular material. By immunoblotting, CC expression was strongly increased in IBM muscle as compared to the controls. By immunoprecipitation/immunoblotting experiments, CC coimmunoprecipitated with AβPP, both in s-IBM muscle and in AβPP-overexpressing cultured normal human muscle fibers. Our studies (i) demonstrate for the first time that CC physically associates with AβPP, and (ii) suggest that CC may play a novel role in the s-IBM pathogenesis, possibly by influencing AβPP processing and Aβ deposition.